From c64f2030a175341ee8943757d12dcf91f5af829c Mon Sep 17 00:00:00 2001
From: Marius Greuel <greuelm@mgtek.com>
Date: Thu, 5 May 2022 21:42:27 +0200
Subject: [PATCH] Improve micronucleus bootloader user experience for
 unresponsive USB devices

---
 src/micronucleus.c | 43 ++++++++++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/micronucleus.c b/src/micronucleus.c
index b8d9d7ee..28dac2cb 100644
--- a/src/micronucleus.c
+++ b/src/micronucleus.c
@@ -139,6 +139,22 @@ static int micronucleus_check_connection(pdata_t* pdata)
     }
 }
 
+static bool micronucleus_is_device_responsive(pdata_t* pdata, struct usb_device* device)
+{
+    pdata->usb_handle = usb_open(device);
+    if (pdata->usb_handle == NULL)
+    {
+        return false;
+    }
+
+    int result = micronucleus_check_connection(pdata);
+
+    usb_close(pdata->usb_handle);
+    pdata->usb_handle = NULL;
+
+    return result >= 0;
+}
+
 static int micronucleus_reconnect(pdata_t* pdata)
 {
     struct usb_device* device = usb_device(pdata->usb_handle);
@@ -696,6 +712,7 @@ static int micronucleus_open(PROGRAMMER* pgm, char* port)
     usb_init();
 
     bool show_retry_message = true;
+    bool show_unresponsive_device_message = true;
 
     time_t start_time = time(NULL);
     for (;;)
@@ -717,6 +734,19 @@ static int micronucleus_open(PROGRAMMER* pgm, char* port)
                     pdata->major_version = (uint8_t)(device->descriptor.bcdDevice >> 8);
                     pdata->minor_version = (uint8_t)(device->descriptor.bcdDevice >> 0);
 
+                    if (!micronucleus_is_device_responsive(pdata, device))
+                    {
+                        if (show_unresponsive_device_message)
+                        {
+                            avrdude_message(MSG_INFO, "%s: WARNING: Unresponsive Micronucleus device detected, please reconnect....\n",
+                                progname);
+
+                            show_unresponsive_device_message = false;
+                        }
+
+                        continue;
+                    }
+
                     avrdude_message(MSG_NOTICE, "%s: Found device with Micronucleus V%d.%d, bus:device: %s:%s\n",
                         progname,
                         pdata->major_version, pdata->minor_version,
@@ -744,19 +774,6 @@ static int micronucleus_open(PROGRAMMER* pgm, char* port)
                     {
                         avrdude_message(MSG_INFO, "%s: ERROR: Failed to open USB device: %s\n", progname, usb_strerror());
                     }
-                    else
-                    {
-                        // Send a dummy request to check for a unresponsive USB device.
-                        int result = micronucleus_get_bootloader_info(pdata);
-                        if (result < 0)
-                        {
-                            avrdude_message(MSG_NOTICE, "%s: WARNING: Failed to probe device (error %d), skipping...\n",
-                                progname, result);
-
-                            usb_close(pdata->usb_handle);
-                            pdata->usb_handle = NULL;
-                        }
-                    }
                 }
             }
         }